The immune system of vertebrates is extremely complex and disorders of the immune system are likewise complicated. The innate immune system, also called the non-specific immune system, includes cells that defend an organism in a non-specific manner. The innate immune system is distinct from the adaptive immune system which specifically recognizes antigens and provides long-term protection. The innate immune system is characterized antigen-independent response and exposure of the innate immune system does not result in immunologic memory. Cells of the innate immune system include dendritic cells, mast cells, macrophages, natural killer cells, neutrophils, basophils and eosinophils.
Due to the complexity of the vertebrate immune system, diseases and defects are often difficult to characterize and treat. There is a continuing need for animal models which allow for isolation of aspects of the innate immune response, providing methods and compositions useful, for example, for identification of effective medical and pharmaceutical treatments of diseases and defects of the innate immune system.